The National Security Agency is America's largest, most costly, and by far most secret intelligence agency. Because its mandate is to eavesdrop on all forms of communications, from email messages to cell phones calls to Google searches to Tweets, it is also the agency that poses the greatest potential harm to the privacy of American citizens. What few outside the intelligence community knew, until Wired's April cover story, was just how much private data the agency was collecting, where they would store it all, how they would analyze it, and how much of a threat this capability posed to Americans. In the article I describe the agency's hidden growth over the past decade, spending tens of billions of dollars on new eavesdropping centers around the county, in Georgia, Texas, Colorado and Hawaii. Most importantly, I focused on the final piece in that complex technological puzzle, a gargantuan and highly secret facility where all of that intercepted communications would be stored and analyzed. At a million square feet, the Bluffdale, Utah center could potentially hold up to a yottabyte of data, somewhere around 500 quintillion (500,000,000,000,000,000,000) pages of text, much of that communications to and from American citizens. I also revealed for the first time the NSA's highly secret new supercomputer complex in Oak Ridge, Tennessee. To analyze the mountains of data in the Bluffdale center, much of it encrypted, the agency's Oak Ridge scientists are working on a computer designed to operate at zetaflop speeds - a billion billion operations a second. Thus, the article outlines for the first time the NSA's growing -- and increasingly dangerous -- eavesdropping capabilities.